Method of and apparatus for evaporating liquids



Dec. 6, 1949 A. scHRANER ET AL METHOD OF AND APPARATUS FOR EVAPORATING LIQUIDS 2 Sheets-Sheet l Filed Feb. 26, 1948 33 /l/ AI Il ll lf 277 Ven (fo/15 Dec. 6, 1949 A. SCHRANK-:Fe ET AL METHOD OF AND APPARATUS FOR EVAPORATING LIQUIDS 2 Sheets-Sheet 2 Filed Feb. 26, 1948 Patented Dec. 6, 1949 METHOD 0F AND APPARATUS FOR EVAPORATIN G LIQUIDS Alfred Schraner, Zurich, and Josef Spirig, Dietikon, Switzerland, assgnors to Vapor Rapid A. G., Vaduz, Liechtenstein Application February 2.6, 1948, Serial No. 11,295 In Switzerland July 6, 1943 section 1, rubinl Law 690, August s, 1946 Patent expires July 6, 1963 This invention relates to a method oi evaporating liquids, in particular of water, and to an apparatus for carrying out such method.

It has been proposed before to squirt water in form oi drops onto heated surfaces where it is evaporated.

The new method comprises conducting the atomized liquid over bare electrical` metallic resistors which are heated to such temperature that they would melt, were they not constantly cooled by the atomized liquid. The evaporation may take place under a pressure higher than atmospheric pressure.

rIhe apparatus for carrying out the method, suitably comprises a nozzle which atomizes the 'pressurized liquid and brings same, in such atomized state, into the range of electrical heating-resistors. The latter suitably are formed of metal wires disposed in a plurality of layers which may be series-connected in the direction of the flow so as to be covered, one after the other, by the atomized liquid, and, thereby, cooled. The wires of adjacent layers suitably are disposed obliquely to each other.

The metallic wires advantageously are disposed in individual replaceable elements which may be electrically connected in any suitable manner.

Two forms of invention, applying to an apparatus for carrying out the inventive method, are shown in the accompanying drawing, in which- Fig. l shows a first form in vertical section,

Figs. 2 and 3 each a detail thereof, in plan View and cross section respectively,

Fig. 4 a cross-section through the second form,

Fig. 5 a portion of the metal-wire support in plan view, and

Figs. 6 and '7 show details of the wire attachment.

A water supply line 2 is connected to a conical bell I, and includes a stop valve 3. The line 2 opens, via an atomizer nozzle 4, into the bell I. A cup 5 is secured to the bottom of the latter, and a steam discharge line 6 is connected thereto. The cup 5 and bell I rest on legs l. A plurality of cooling-fins 8 is provided on the circumference of bell I. A plurality of enameled metallic rings I0 are disposed, stackwise, in the upper portion of cup 5. The rings iii are secured., readily detachable and replaceable, on two studs II which at the same time serve as current leads. On the inner circumference of each ring ID. lugs I2 are bent off from the ring material, each second lug pointing upward, while the intermediate lugs are bent downward (Figs.

3 Claims. (Cl. 219-39) 2, 3). Bare, i. e. noninsulated heating-wires I4,

wound meanderlike, are secured to the lugs I2 of each ring ID in such way that wires situated directly below each other stand obliquely or vertically to each other. The arrangement also may be such that all the wires of a ring are disposed parallel to each other, but at right angles to those of the adjacent ring. Each ring, therefore, comprises two systems of wire Id. One end of each system is conductively connected to one stud E I, and the other to the other stud I I. The full voltage applied across the studs II, therefore, is applied to each wire system, i. e. all the wire systems are electrically parallel-connected. The rings are isolated from the studs by virtue of the above-mentioned layer of enamel. A oat-chamber I6 is disposed in the bottommost portion of cup 5, and its drain is controlled by a The liquid atomized in the nozzle 4 is injected between the heating-wires, where it evaporates. The said wires are heated to such a degree that they would melt, were they not continuously cooled by the atomized liquid.

The steam produced escapes through the line 6. Any water of condensation is trapped in chamber IS, and will raise the float I'I after having reached a certain level, thereby permitting such water to flow off through the line 20.

Instead of squirting the water, in the manner described, onto heating-wires disposed in planes in front of the nozzle, the latter also may be entirely or partly enveloped by heating-wires, e. g. in such a way that the nozzle is disposed inside of spherical, cylindrical or conical wire fabrics. The design also could be such that the cylindrical jacket extends coaxially to the direction of the jet and envelopes part of the jet. In the second form of invention, shown in Figs. 4 to '7, a cylindrical vessel 2| is provided with a cover 22 and disposed inside of an outer vessel 23. A heatinsulating layer 24 is provided intermediate of the vessels 2| and 23. The said vessels 2l, 23 are supported on legs 25. The liquid to be evaporated is supplied through a line 26 which terminates in an atomizer nozzle 2l. The liquid, for eX- ample water, impinges in form of an upwardly directed conical jet 2B onto the resistor wires 29 which are heated, as mentioned before, substantially to melting temperature. The atomized liquid cools the said wires so that they will not melt, and thereby evaporates. The said wires 29, which suitably are helically adapted, are inserted into downwardly narrowing slots 35i of insulating plates 3| and secured therein. As may 3 be seen from Fig. 5, the said wires form individual rings, and two rings each are supported on the same plate 3l. The latter are secured to metallic rings 3210i U-shaped cross-section, -and all the metallicrings are secured to' the'a'rms 33 of va spider support which is connected, by means of a screw 34, to a stud 35 which is centrally secured in the cover 22 and projects downward therefrom. The arms 33 are arranged on a 'downward'slope sc that the rings of resistor-wire 29 carriedthereby are disposed pairwise on `top Tof each other` and decrease in diameter in'anzupward'direction. All the resistor-wires 29 together form an umbrella-like structure, in thatthe said wires-are disposed on conical surfaces. lCurrent is supplied to the resistor wires through leads 36 which pass through the wall of vessel 2| bymeanspf anfinsulating-bush 31. A plurality of leads- 36 are provided.

The steam producedvwhen the atomize'd liquid .impinges on the red-hotresistor wires V29, is disl charged'through the apertures 3B of a tubular ring 39 and flows linto Ithegriser1H):communicating l,with

the upperholl'ow portion lll of stud 35. A coiled 4 a source of electrical current and leads carried in bushings through the Wall of the vessel to conneet with the said wires for the purpose of heatvingthe latter to generatesteam from the atom- :ized liquid, an apertured annular steam receiving pipe disposed at the bottom of the Vessel, pipe means for discharging the steam from the said annular pipe Vupwardly into the range oi said 'screen structure, and a superheater pipe coil arranged in dome shape at the ceiling of the Vessel and connected at one end to said pipe means and atthe vother end to a pipe carried through the :wall-of the vessel for carrying away superheated steam.

2. 4A Vapor generator comprising parts and portions set out in claim l, in which the said wires 'are circularly'mounted in plural tiers in said screen structure.

3. A vapor generator set out in claim 2, in which the said wires are disposed pairwise in each tier.

SCHRANER, JOSEF SPIRIG.

REFERENCES CITED The following references are of record in vthe lle of vthis patent:

UNITED STATES PATENTS 

